thanx Peter, tiger fish you say,now that is a name I know, but honestly wouldn't know what is looks like if that is what it is, fishermen must drool in KNP, there were quite a few cruising in the shallows, along with a tiny croc about 30cm big

Tigerfish are inhabitants of open, well-oxygenated waters such as is found in the larger rivers and lakes. In the Park, it is hardly ever found in the smaller tributaries of the perennial rivers, except in those where large bodies of open waters occur, such as in the Shingwedzi and Mphongolo rivers.
Breeding does not take place in Park watersand there would appear to be a winter migrationof tigerfish back to the lowlands of Mocambique, where they spawn during December and January along the shallow, grasscovered fringes of lakes and small streams.
Adult tigerfish are voracious feeders and may consume as much as 8% of their own weight during a single meal. Common prey species are small Barbus and Labeo spp., as well as bottom dwelling gobies.
The principal enemy of young tigerfish is undoubtedly adults of the species, although predatory birds such as fish eagles also take their toll. Lage tigerfish are probably only preyed upon by crocodiles, otters and man.

Distribution: The perennial rivers of the Park, particulairy the eastern sections below 1.000 ft elevation, as well as isolated pools in the Mutale, Mhpongolo, Shingwedzi, Tsende and Mbyamiti rivers.

(Tol Pienaar, The freshwater fishes of the KNP, 1968)

Not posting much here anymore, but the photo's you can follow here There is plenty there.

Feel free to use any of these additional letters to correct the spelling of words found in the above post: a-e-t-n-d-i-o-s-m-l-u-y-h-c

Tol Pienaar's work is quite old. It was thought that the tiger fish breed on floodplains in the rainy season. Mpumalanga Conservation did research on tiger fish in the Komati/Crocodile Rivers. I recall being told that these fish breed on sandbanks below natural and man made weirs in the rivers. Breeding occurs above Komatipoort in the river below irrigation dams. Regards, Agama